Hunting is an ancient tradition that is still practiced for both survival and sport. In both cases the hunter's goal is to harvest the animal as humanely and quickly as possible.
While hunting using firearms is the most common form of hunting, especially when hunting big game such as elk and deer, hunting using a bow and arrow remains a popular activity. Bow hunters enjoy the increased challenge of hunting an animal using only mechanical means. In other words, it can be more physically challenging to harvest animals using a mechanically launched projectile, such as an arrow, than it is when using a firearm that accelerates its projectile as a result of a controlled explosion, often with the aid of ancillary sighting devices which can provide increase long range accuracy This difference, however, can pose a problem because it can be more difficult to bring down an animal as efficiently with an arrow as it is with a bullet.
The archery industry has strived to increase the killing force of the bow and arrow system with various improvements. For instance, bows were made with stronger pulling force, which resulted in the arrow being launched with higher velocity. The higher velocity translates to more damage done by the arrow, which results in quicker, more efficient harvesting of animals. When bows approached the limit of not being able to be effectively drawn and held by the archer, compound bows were developed that created additional mechanical force by using cams or lobed pulleys in conjunction with the bow and bowstring. Because of their let-off, these compound bows can have increased launching force and the ability to hold the bow at full draw for precision targeting with the use of a bow sight. Compound bows are now the most common bow used in hunting, especially big game hunting.
Arrows and especially arrowheads have also changed over time to increase the likelihood that the animal is quickly brought down. Broadheads have evolved from the stone heads of ancient times to the current broadheads made of metal. Generally broadheads have two to four fixed blades which may be finely sharpened to deeply penetrate the animal and cause massive internal bleeding. This minimizes the time between arrow penetration and animal expiration. Further, if the arrow does not kill quickly enough, the animal may travel significant distance after it is struck, increasing the likelihood that the animal may not be recovered, or that the animal unnecessarily suffers before dying.
Mechanical broadheads may also be used by hunters. Mechanical broadheads have two positions, a retracted position for flight and a second position that is deployed after the arrow strikes the animal. When the arrow strikes the animal, the broadhead switches from the flight position to the strike position, exposing its blades, which causes more damage to the animal than if the broadhead remained in the flight position. Mechanical broadheads generally penetrate the animal less deeply than fixed broadheads because some of the kinetic energy of the arrow is used to release the mechanical broadhead, although the increased damage to the animal that a mechanical broadhead causes may outweigh the kinetic energy loss, as they can have greater flight aerodynamics in the retracted position and a larger diameter cutting capability in the fully deployed open position upon impact with target
Mechanical broadheads do not always work as intended, however. Depending on such variables as velocity, arrow weight, strike location, strike angle, etc., the mechanical broadheads may not fully deploy their mechanical blades or they may use too much of the arrow's kinetic energy to cause sufficient damage to the animal to bring it down quickly and humanely. In these cases it may have been better to use a fixed broadhead rather than the malfunctioning mechanical broadhead. The hunter does not know before the arrow strike, however, whether the mechanical or fixed broadhead would have been better for the particular shot. Lack of penetration has been cited as a significant factor in non-lethal shots which are, of course, to be avoided.
Embodiments of the invention address these and other limitations of the prior art.